Patent Literature 1 (JP 2009-77016A) discloses an input circuit which converts a high potential signal into a low potential signal. Here, the potential level of the high potential signal changes in a range from a ground potential GND to a high power supply potential VCCH, and the potential level of the low potential signal changes in a range from the ground potential GND to a low power supply potential VCCL. The high power supply potential VCCH is higher than the low power supply potential VCCL (VCCH>VCCL). In Patent Literature 1, all of transistors in the input circuit are formed from low withstanding voltage transistors.
Patent Literature 2 (JP 2006-114733A) discloses a trimming resistance. The trimming resistance is provided with a first resistor, a second resistor and a semiconductor switch. The first resistor is formed on a semiconductor substrate to be possible to be trimmed. The second resistor is formed on the semiconductor substrate to be possible to be trimmed. Also, the second resistor is connected with the first resistor and it is possible to configure a synthesized resistance with the first resistor between two terminals. The semiconductor switch is formed on the semiconductor substrate and is connected with the first resistor and the second resistor. The semiconductor switch is used to reduce a resistance value between the two terminals in the on-state less than the resistance value between the two terminals in the off-state.